POS0507 OSTEOPOROSIS IN SYSTEMIC SCLEROSIS: A CROSS-SECTIONAL STUDY IN A MONOCENTRIC CENTER. ANY ROLE FOR CALCINOSIS?
Authors: M. Cadar, G. Pellegrino, D. M. Reza Beigi, I. Bisconti, F. R. DI Ciommo, S. Truglia, F. Conti, V. Riccieri
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Systemic sclerosis (SSc) is a rare and progressive autoimmune disease, that has been associated with an increased risk of osteoporosis (OP), but risk factors are still debated <sup>[1,2]</sup>. <h3>Objectives</h3> The aim of our study was to investigate the risk factors for osteoporosis in SSc and to evaluate if any feature of the disease could increase the risk of osteoporosis. <h3>Methods</h3> In this cross-sectional study we included 60 consecutive patients, fulfilling the 2013 ACR/EULAR classification criteria of SSc<sup>[3]</sup>, attending our Rheumatology Unit from July to December 2022. All the 60 patients performed a Dual-energy X-ray absorptiometry (DXA) between 2020 and 2022. Osteoporosis was defined as a T score less than -2.5 SD and osteopenia as a T-score between -1.0 and -2.5 SD, according to WHO definitions. We divided patients in two groups according to the diagnosis of osteoporosis (OP+) and non osteoporosis including osteopenia (OP-). We collected the main clinical-demographic and laboratory features of the patients and we assess the presence of any association with OP. <h3>Results</h3> All 60 patients were women with an average age (mean±SD) of 70.5±10.1 years, 35 had a diagnosis of osteoporosis (OP+ group) and 25 patients were included in OP- group, in which 17 patients had osteopenia. The two groups were comparable for age, disease duration, menopause and smoking habit. We found statistically significant differences between the two groups with BMI (21.97±3.47 in OP+ vs 24.04±3.63 in OP-, p=0.04), modified Rodnan Skin Score (mRSS) (8.91±12.19 vs 3.20±4.71, p=0.03) and presence of calcinosis (12 in OP+ vs 1 in OP-, p=0.005), pitting scars (17 vs 5, p=0.03) and telangiectasia (28 vs 13, p=0.02). Performing simple logistic regression analyses we confirmed the association of calcinosis (OR 12.52, CI 2.2-237.3, p=0.02), pitting scars (OR 2.02, CI 1.08-11.97, p=0.04) and telangiectasia (OR 2.24, CI 1.21-12.09, p=0.02) with the presence of OP. There was no difference between the two groups for NVC scleroderma pattern, autoantibodies and presence of digital ulcers. (Table 1). <h3>Conclusion</h3> This retrospective study confirms the association of OP with lower BMI in SSc. An increased mRSS and the presence of calcinosis, telangiectasias and pitting scars were also associated to OP in our patients. These SSc features deserve to pinpoint an early evaluation of bone health in our patients and an early referral to DXA, independently from the traditional risk factors of OP. Of interest, in our opinion, is the rather high prevalence of calcinosis in the OP+ group, confirming data from other authors<sup>[4]</sup> and suggesting a possible common pathogenically pathway in calcinosis development. <h3>References</h3> [1]Tu X, et al. <i>Clin Rheumatol</i>. 2022 [2]Marot M, et al. <i>Oncotarget</i>. 2015 [3]van den Hoogen F, et al. <i>Ann Rheum Dis</i>. 2013 [4]Valenzuela A, et al. <i>Semin Arthritis Rheum</i>. 2016 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.